The candidate has a clinical background in neurology with an expertise in movement disorders and has completed a two year NIH-funded fellowship through the Department of Neurology in Experimental Therapeutics. This fellowship provided the candidate with both theoretical knowledge and practical experience pertaining to the design and conduct of clinical trials. She has focussed most of her efforts thus far on the understanding and treatment of the behavioral aspects of Parkinson's disease (PD) The candidate's short term goals include the following: 1) to increase her knowledge of basic pharmacology and gain experience using techniques relevant to pharmacologic mechanism oriented research, 2) to gain a better understanding of molecular medicine, 3) to obtain training in psychiatric assessment techniques, 4) to expand her knowledge of areas fundamental to clinical investigation including biostatistics, epidemiology and outcomes research. The focus of her research plan during this career development award will be understanding mood fluctuations in PD. Mood fluctuations have been reported in up to 2/3 of advanced PD patients who experience motor fluctuations. These can be frequent, dramatic and distressing. Research involving the phenomenology and underlying mechanisms of mood fluctuations in PD has been limited. The specific aims of this study are to: 1) better understand the phenomenology of mood fluctuations in PD (frequency, quality, magnitude), 2) better understand the relationship between mood fluctuations and more pervasive depressive disorders in PD, 3) clarify the temporal relationship between changes in mood and motor states in PD, 4) elucidate the neurobiological mechanisms of changing mood states in PD and to determine, in particular, whether mood fluctuations in PD are the result of dopamine dysregulation, and 5) gather preliminary information regarding the optimal treatment of mood disorders in PD. These findings may lead to the development of therapeutic interventions for patients with PD who suffer from these disabling fluctuations on a daily basis. It may also provide a better understanding of the mechanisms responsible for more pervasive forms of depression in PD, and perhaps even in primary psychiatric mood disturbances.